At this time of the year the trees have lost their leaves and most other plants have withered away from the frosts. But if you are out walking in the woods you might notice a sweet fragrance in the air. If you follow your nose you will usually find a small understory tree covered in fragrant yellow-fringed flowers. This is witch hazel (Hamamelis virginiana), Wisconsin's only autumn blooming tree.

Witch hazel has several unique adaptations. The flowers have 4 long petals that curl up during cold temperatures and unfurl during warm days. Flies in the genus Bradysia (dark-winged fungus gnats) are the most common insects to pollinate the flowers, but is likely that other flies, and other late flying bees and wasps are also pollinators.

The fruit is dry and woody and tends to stay on the branches through the winter,
after expelling the seeds in the fall. Two shiny black seeds are explosively discharged as far as 10 meters with a gun like crack, often startling walkers as they pass by. The sound is so distinctive that its other common name is "snapping hazel". This dispersal mechanism ensures that new seedlings will germinate far away from the parent tree.

If you examine the branches you will find flowers, buds, and fruit on the branches at the same time. It is the only North American tree with this trait. In fact, the generic name, Hamamelis, means "together with fruit" referring to this trait.

This shrub has become a favorite in the winter garden, but be aware most horticultural varieties of witch hazel are not native. The two most popular varieties are Hamamelis japonica and Hamamelis mollis, both from Asia and a hybrid Hamamelis x intermedia (red flowered).

Witch hazel's medicinal uses as an anti-inflammatory and astringent have long been recognized. Poultices of the leaves and twigs were used by Native Americans and passed along to European settlers.